1. Articles from Tien Yin Wong

    1-24 of 40 1 2 »
    1. Optical Coherence Tomography Classification Systems for Diabetic Macular Edema and Their Associations With Visual Outcome and Treatment Responses

      Optical Coherence Tomography Classification Systems for Diabetic Macular Edema and Their Associations With Visual Outcome and Treatment Responses

      Optical coherence tomography (OCT) is an invaluable imaging tool in detecting and assessing diabetic macular edema (DME). Over the past decade, there have been different proposed OCT-based classification systems for DME. In this review, we present an update of spectral-domain OCT (SDOCT)-based DME classifications over the past 5 years. In addition, we attempt to summarize the proposed OCT qualitative and quantitative parameters from different classification systems in relation to disease severity, risk of progression, and treatment outcome. Although some OCT-based measurements were found to have prognostic value on visual outcome, there has been a lack of consensus or guidelines ...

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    2. Six-year incidence of age-related macular degeneration and correlation to OCT-derived drusen volume measurements in a Chinese population

      Six-year incidence of age-related macular degeneration and correlation to OCT-derived drusen volume measurements in a Chinese population

      Aims To report the 6-year incidence of optical coherence tomography (OCT)-derived age-related changes in drusen volume and related systemic and ocular associations. Methods Chinese adults aged 40 years and older were assessed at baseline and 6 years with colour fundus photography (CFP) and spectral domain (SD) OCT. CFPs were graded for age-related macular degeneration (AMD) features and drusen volume was generated using commercially available automated software. Results A total of 4172 eyes of 2580 participants (mean age 58.12±9.03 years; 51.12% women) had baseline and 6-year follow-up CFP for grading, of these, 2130 eyes of 1305 ...

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    3. A Multitask Deep-Learning System to Classify Diabetic Macular Edema for Different Optical Coherence Tomography Devices: A Multicenter Analysis

      A Multitask Deep-Learning System to Classify Diabetic Macular Edema for Different Optical Coherence Tomography Devices: A Multicenter Analysis

      OBJECTIVE Diabetic macular edema (DME) is the primary cause of vision loss among individuals with diabetes mellitus (DM). We developed, validated, and tested a deep learning (DL) system for classifying DME using images from three common commercially available optical coherence tomography (OCT) devices. RESEARCH DESIGN AND METHODS We trained and validated two versions of a multitask convolution neural network (CNN) to classify DME (center-involved DME [CI-DME], non-CI-DME, or absence of DME) using three-dimensional (3D) volume scans and 2D B-scans, respectively. For both 3D and 2D CNNs, we used the residual network (ResNet) as the backbone. For the 3D CNN, we ...

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    4. Computer-aided detection and abnormality score for the outer retinal layer in optical coherence tomography

      Computer-aided detection and abnormality score for the outer retinal layer in optical coherence tomography

      Background: To develop computer-aided detection (CADe) of ORL abnormalities in the retinal pigmented epithelium, interdigitation zone and ellipsoid zone via optical coherence tomography (OCT). Methods: In this retrospective study, healthy participants with normal ORL, and patients with abnormality of ORL including choroidal neovascularisation (CNV) or retinitis pigmentosa (RP) were included. First, an automatic segmentation deep learning (DL) algorithm, CADe, was developed for the three outer retinal layers using 120 handcraft masks of ORL. This automatic segmentation algorithm generated 4000 segmentations, which included 2000 images with normal ORL and 2000 (1000 CNV and 1000 RP) images with focal or wide defects ...

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    5. Utilisation of poor-quality optical coherence tomography scans: adjustment algorithm from the Singapore Epidemiology of Eye Diseases (SEED) study

      Utilisation of poor-quality optical coherence tomography scans: adjustment algorithm from the Singapore Epidemiology of Eye Diseases (SEED) study

      Purpose To evaluate the effect of signal strength (SS) on optical coherence tomography (OCT) parameters, and devise an algorithm to adjust the effect, when acceptable SS cannot be obtained. Methods 5085 individuals (9582 eyes), aged ≥40 years from the Singapore Epidemiology of Eye Diseases population-based study were included. Everyone underwent a standardised ocular examination and imaging with Cirrus HD-OCT. Effect of SS was evaluated using multiple structural breaks linear mixed-effect models. Expected change for increment in SS between 4 and 10 for individual parameter was calculated. Subsequently we devised and evaluated an algorithm to adjust OCT parameters to higher SS ...

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    6. Quantitative OCT angiography of the retinal microvasculature and choriocapillaris in highly myopic eyes with myopic macular degeneration

      Quantitative OCT angiography of the retinal microvasculature and choriocapillaris in highly myopic eyes with myopic macular degeneration

      Purpose: To quantify retinal and choriocapillaris (CC) microvasculature in highly myopic (HM) eyes with myopic macular degeneration (MMD) using swept-source optical coherence tomography angiography (SS-OCTA). Methods: 162 HM eyes (spherical equivalent ≤ -6.0 dioptres or axial length (AL) ≥26.5 mm) from 98 participants were enrolled, including 60 eyes (37.0%) with tessellated fundus, 54 eyes (33.3%) with peripapillary diffuse chorioretinal atrophy (PDCA), 27 eyes (16.7%) with macular diffuse chorioretinal atrophy (MDCA) and 21 eyes (13.0%) with patchy or macular atrophy. PLEX Elite 9000 SS-OCTA was performed to obtain perfusion densities (PD) of the superficial and deep ...

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    7. DIABETIC MACULAR ISCHEMIA: Correlation of Retinal Vasculature Changes by Optical Coherence Tomography Angiography and Functional Deficit

      DIABETIC MACULAR ISCHEMIA: Correlation of Retinal Vasculature Changes by Optical Coherence Tomography Angiography and Functional Deficit

      Purpose: To examine the relationship between macular microvasculature parameters and functional changes in persons with diabetic retinopathy (DR). Methods: Cross-sectional study of 76 eyes with varying levels of DR. Optical coherence tomography angiography (OCTA) quantified superficial and deep perifoveal vessel densities and foveal avascular zone areas. Retinal sensitivity was measured using microperimetry . Optical coherence tomography angiography parameters and retinal sensitivity were correlated. Results: Deep perifoveal vessel density decreased with increasing severity of DR (adjusted mean 51.93 vs. 49.89 vs. 47.96, P -trend = 0.005). Superficial and deep foveal avascular zone area increased with increasing DR severity (adjusted ...

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    8. Detection of features associated with neovascular age-related macular degeneration in ethnically distinct data sets by an optical coherence tomography: trained deep learning algorithm

      Detection of features associated with neovascular age-related macular degeneration in ethnically distinct data sets by an optical coherence tomography: trained deep learning algorithm

      Background The ability of deep learning (DL) algorithms to identify eyes with neovascular age-related macular degeneration (nAMD) from optical coherence tomography (OCT) scans has been previously established. We herewith evaluate the ability of a DL model, showing excellent performance on a Korean data set, to generalse onto an American data set despite ethnic differences. In addition, expert graders were surveyed to verify if the DL model was appropriately identifying lesions indicative of nAMD on the OCT scans. Methods Model development data set—12 247 OCT scans from South Korea; external validation data set—91 509 OCT scans from Washington, USA ...

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    9. Systemic hypertension associated retinal microvascular changes can be detected with optical coherence tomography angiography

      Systemic hypertension associated retinal microvascular changes can be detected with optical coherence tomography angiography

      A major complication of hypertension is microvascular damage and capillary rarefaction is a known complication of hypertensive end-organ damage which confers a higher risk of systemic disease such as stroke and cardiovascular events. Our aim was to study the effect of hypertension on the retinal microvasculature using non-invasive optical coherence tomography angiography (OCTA). We performed a case-control study of 94 eyes of 94 participants with systemic hypertension and 46 normal control eyes from the Singapore Chinese Eye Study using a standardized protocol to collect data on past medical history of hypertension, including the number and type of hypertensive medications and ...

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    10. Quantitative Microvascular Analysis With Wide-Field Optical Coherence Tomography Angiography in Eyes With Diabetic Retinopathy

      Quantitative Microvascular Analysis With Wide-Field Optical Coherence Tomography Angiography in Eyes With Diabetic Retinopathy

      Importance Wide-field optical coherence tomographic angiography (OCTA) may provide insights to peripheral capillary dropout in eyes with diabetic retinopathy (DR). Objective To describe the diagnostic performance of wide-field OCTA with and without large vessel removal for assessment of DR in persons with diabetes. Design, Setting, and Participants This case-control study was performed from April 26, 2018, to April 8, 2019, at a single tertiary eye center in Singapore. Case patients were those with type 2 diabetes for more than 5 years and bilateral DR diagnosed by fundus imaging; control participants included those with no self-reported history of diabetes, a fasting ...

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    11. DIABETIC MACULAR ISCHEMIA Correlation of Retinal Vasculature Changes by Optical Coherence Tomography Angiography and Functional Deficit

      DIABETIC MACULAR ISCHEMIA Correlation of Retinal Vasculature Changes by Optical Coherence Tomography Angiography and Functional Deficit

      Purpose: To examine the relationship between macular microvasculature parameters and functional changes in persons with diabetic retinopathy (DR). Methods: Cross-sectional study of 76 eyes with varying levels of DR. Optical coherence tomography angiography (OCTA) quantified superficial and deep perifoveal vessel densities and foveal avascular zone areas. Retinal sensitivity was measured using microperimetry . Optical coherence tomography angiography parameters and retinal sensitivity were correlated. Results: Deep perifoveal vessel density decreased with increasing severity of DR (adjusted mean 51.93 vs. 49.89 vs. 47.96, P -trend = 0.005). Superficial and deep foveal avascular zone area increased with increasing DR severity (adjusted ...

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    12. Artificial intelligence, the internet of things, and virtual clinics: ophthalmology at the digital translation forefront

      Artificial intelligence, the internet of things, and virtual clinics: ophthalmology at the digital translation forefront

      The advent of artificial intelligence (AI), big data, and the next-generation telecommunication network (5G) has generated enormous interest in digital health. Digital health comprises overlapping areas ranging from AI, the internet of things, electronic health, and telehealth to the analysis and use of big data. 1 With substantial innovation opportunities in digital health, WHO published a set of guidelines earlier this year, 1 advising potential researchers and innovators on how to harness this technology to create evidence-based interventions within real-world settings to improve patients' outcome. Here, we highlight some of the new developments in ophthalmology, focusing on AI and other ...

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    13. Macular Vessel Density Measured With Optical Coherence Tomography Angiography and Its Associations in a Large Population-Based Study

      Macular Vessel Density Measured With Optical Coherence Tomography Angiography and Its Associations in a Large Population-Based Study

      Purpose : We investigate macular perfusion and the systemic and ocular associations in a population-based setting. Methods : In this cross-sectional study, 2018 adults residing in Hong Kong underwent detailed ophthalmic examinations after consenting to participate. Macular perfusion was measured with optical coherence tomography angiography (OCTA) using the split-spectrum amplitude decorrelation angiography algorithm. The parafoveal flow index and vessel area density were quantified using automated custom-built software. Results : Of the 2018 participants, the OCTA measurements were available for 1940, and 1631 (84.1%) had good quality scans. The right eyes of these 1631 participants (43.1% men) were included for final analysis ...

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    14. Artificial Intelligence in Diabetic Eye Disease Screening

      Artificial Intelligence in Diabetic Eye Disease Screening

      Systematic or national screening programs for diabetic retinopathy (DR) and diabetic macular edema (DME), using digital fundus photography and optical coherence tomography (OCT), are currently implemented at primary care level, aiming to provide timely referral for vision-threatening DR and DME to ophthalmologists for timely treatment and vision loss prevention. However, interpretation of retinal images requires specialized knowledge and expertise in diabetic eye disease. Furthermore, current DR screening programs are capital- and labor-intensive, which makes it difficult to rapidly scale up and expand diabetic eye screening to meet the needs of this growing global epidemic. Deep learning (DL), a new branch ...

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    15. Impact of systemic vascular risk factors on the choriocapillaris using optical coherence tomography angiography in patients with systemic hypertension

      Impact of systemic vascular risk factors on the choriocapillaris using optical coherence tomography angiography in patients with systemic hypertension

      We investigated the characteristics of the choriocapillaris flow voids using optical coherence tomography angiography (OCTA) in 85 patients (164 eyes) with hypertension (mean ± SD age, 56 ± 11 years; 45% women; 20% poorly controlled BP; 16% diabetes) who are without ocular diseases and determined possible correlations with systemic vascular risk factors. Data on 24-hour ambulatory blood pressure (BP), serum creatinine, and urine microalbumin/creatinine ratio (MCR) were collected. Estimated glomerular filtration rate (eGFR) was calculated based on CKD-EPI Creatinine Equation. OCTA imaging (6 × 6 mm scans; AngioVue) with quantitative microvascular analysis of the choriocapillaris was performed. Linear regression was used to ...

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    16. Artificial intelligence and deep learning in ophthalmology

      Artificial intelligence and deep learning in ophthalmology

      Artificial intelligence (AI) based on deep learning (DL) has sparked tremendous global interest in recent years. DL has been widely adopted in image recognition, speech recognition and natural language processing, but is only beginning to impact on healthcare. In ophthalmology, DL has been applied to fundus photographs, optical coherence tomography and visual fields, achieving robust classification performance in the detection of diabetic retinopathy and retinopathy of prematurity, the glaucoma-like disc, macular oedema and age-related macular degeneration. DL in ocular imaging may be used in conjunction with telemedicine as a possible solution to screen, diagnose and monitor major eye diseases for ...

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    17. Correlation of Color Fundus Photograph Grading with Risks of Early Age-related Macular Degeneration by using Automated OCT-derived Drusen Measurements

      Correlation of Color Fundus Photograph Grading with Risks of Early Age-related Macular Degeneration by using Automated OCT-derived Drusen Measurements

      We evaluated automated OCT-derived drusen volume measures in a population-based study (n = 4,512) aged ≥40 years, and its correlation with conventional color fundus photographs (CFP)-derived early AMD features. Participants had protocol-based assessment to capture medical and ocular history, genotyping for SNPs in CFH , ARMS2 , and CETP , CFP-based AMD grading and automated drusen volume based on SD-OCT using built-in software (Cirrus OCT advanced RPE analysis software). Significantly fewer eyes with early AMD features (drusen, hyperpigmentation, soft or reticular drusen) had drusen volume = 0 mm 3 (p < 0.001). In eyes with drusen volume > 0 mm 3 , increasing AMD severity ...

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    18. Comparison Of Optical Coherence Tomography Angiographic Changes After Anti–Vascular Endothelial Growth Factor Therapy Alone Or In Combination With Photodynamic Therapy In Polypoidal Choroidal Vasculopathy

      Comparison Of Optical Coherence Tomography Angiographic Changes After Anti–Vascular Endothelial Growth Factor Therapy Alone Or In Combination With Photodynamic Therapy In Polypoidal Choroidal Vasculopathy

      Purpose: To compare changes in optical coherence tomography angiography in eyes with polypoidal choroidal vasculopathy after treatment with anti–vascular endothelial growth factor monotherapy or combined with photodynamic therapy . Methods: This is a longitudinal case-controlled study. The authors performed optical coherence tomography angiography at baseline and Month 3 in patients with treatment-naive polypoidal choroidal vasculopathy undergoing monotherapy (n = 10) or combination therapy (n = 13). We analyzed flow signal within the outer retina and choriocapillaris using automated segmentation. The authors analyzed the presence of pachyvessels using a 10.4- μ m segment through Haller layer . The changes in each layer were compared ...

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    19. Clinical Use of Optical Coherence Tomography Angiography in Diabetic Retinopathy Treatment Ready for Showtime?

      Clinical Use of Optical Coherence Tomography Angiography in Diabetic Retinopathy Treatment Ready for Showtime?

      Diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) are the 2 advanced stages of diabetic retinopathy (DR) that are the main causes for visual loss in patients with diabetes. Both DME and PDR can be readily diagnosed with clinical examination and, increasingly, by the noninvasive use of optical coherence tomography. However, another, less commonly recognized cause of visual loss in patients with diabetes is diabetic macular ischemia (DMI) in the absence of DME. 1 The understanding of the natural history, risk factors, and functional outcomes of DMI remains limited. This is partly because of the long-standing need for invasive ...

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    20. Identification of imaging features that determine quality and repeatability of retinal capillary plexus density measurements in OCT angiography

      Identification of imaging features that determine quality and repeatability of retinal capillary plexus density measurements in OCT angiography

      Purpose Optical coherence tomography angiography (OCT-A) potentially allows for rapid and non-invasive quantification of retinal capillary plexus density in various disease states. This study aims to identify the key features that influenced the repeatability of OCT-A measurements. Methods We obtained OCT-A images on two separate visits in 44 healthy eyes from 44 subjects, each imaged with using the Topcon DRI OCT Triton imaging system. The parafoveal vessel density within a 1.5 mm radius centred over the fovea was obtained with the built-in tool for the superficial and deep retinal plexuses. Repeatability of vessel density was determined by intraclass correlation ...

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    21. Repeatability and Reproducibility of Retinal Neuronal and Axonal Measures on Spectral-domain Optical Coherence Tomography in Patients with Cognitive Impairment

      Repeatability and Reproducibility of Retinal Neuronal and Axonal Measures on Spectral-domain Optical Coherence Tomography in Patients with Cognitive Impairment

      Background: With increasing interest in determining if measurement of retinal neuronal structure with spectral-domain optical coherence tomography (SD-OCT) is useful in accessing neurodegenerative process in cognitive decline and development of dementia, it is important to evaluate whether the SD-OCT measurements are repeatable and reproducible in patients with Alzheimer’s disease (AD) or mild cognitive impairment (MCI). Methods: This is a retrospective cohort study. Patients with AD or MCI with no change in global clinical dementia rating (CDR) score at 1-year follow-up were eligible to be included. (GC-IPL) Macular ganglion-cell inner plexiform layer (GC-IPL) and peripapillary retinal nerve fiver layer (RNFL ...

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    22. COMPARISON OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHIC CHANGES AFTER ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY ALONE OR IN COMBINATION WITH PHOTODYNAMIC THERAPY IN POLYPOIDAL CHOROIDAL VASCULOPATHY

      COMPARISON OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHIC CHANGES AFTER ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY ALONE OR IN COMBINATION WITH PHOTODYNAMIC THERAPY IN POLYPOIDAL CHOROIDAL VASCULOPATHY

      Purpose: To compare changes in optical coherence tomography angiography in eyes with polypoidal choroidal vasculopathy after treatment with anti-vascular endothelial growth factor monotherapy or combined with photodynamic therapy. Methods: This is a longitudinal case-controlled study. The authors performed optical coherence tomography angiography at baseline and Month 3 in patients with treatment-naive polypoidal choroidal vasculopathy undergoing monotherapy (n = 10) or combination therapy (n = 13). We analyzed flow signal within the outer retina and choriocapillaris using automated segmentation. The authors analyzed the presence of pachyvessels using a 10.4-[mu]m segment through Haller layer. The changes in each layer were compared ...

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    23. Factors affecting signal strength in spectral-domain optical coherence tomography

      Factors affecting signal strength in spectral-domain optical coherence tomography

      Purpose To identify ocular factors that affect signal strength in spectral-domain optical coherence tomography (SD-OCT). Methods Data from 1312 participants of the population-based Singapore Malay Eye Study-2 (SiMES-2) were included in the analysis. All participants underwent standardized ophthalmic examination, including measurements of best-corrected visual acuity (BCVA), refractive error, axial length, corneal curvature and presence of cataracts. Optic disc and macular cube scans were acquired using the Cirrus HD-OCT (software version 6.0, Carl Zeiss Meditec, Dublin, CA, USA). Signal strength of the optical coherence tomography (OCT) scan was recorded for each study eye. Multivariable linear regression analyses were performed to ...

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    24. Artificial Intelligence With Deep Learning Technology Looks Into Diabetic Retinopathy Screening

      Artificial Intelligence With Deep Learning Technology Looks Into Diabetic Retinopathy Screening

      D iabetic retinopathy is a leading cause of vision loss in the United States and globally, particularly among working-aged individuals. Diabetic retinopathy meets all the criteria for screening: first, the condition (diabetic retinopathy) is an important public health care problem; second, the epidemiology and natural history of the condition, including development from asymptomatic latent to severe disease, are adequately understood; third, the screening test (retinal photography) is simple, safe, validated, and acceptable; and fourth, an effective treatment (intravitreous injections of anti–vascular endothelial growth factor or laser therapy for severe diabetic retinopathy or diabetic macular edema [DME]) is available for ...

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    1-24 of 40 1 2 »
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    1. (31 articles) Singapore Eye Research Institute
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